Process and apparatus for producing thermoplastic resins modified with an elastomer

摘要

Elastomer-modified thermoplastics are produced by dewatering a wet thermoplastic-grafted elastomer (D) to a moisture content of 1-50 (preferably 10-40) wt% and compounding with a thermoplastic melt (B) in a continuous kneader-reactor fitted with kneading bars, some of which recirculate the material towards the inlet. A method for the production of elastomer-modified thermoplastics (I) by mixing an elastomer (D) (graft-polymerised with a thermoplastic shell (A)) with a thermoplastic (B), in which a wet graft copolymer (D) is dried to a moisture content of 1-50 (preferably 5-50, especially 10-40) wt% and then mixed into molten thermoplastic (B), and the melting of (D), the alloying of (D) with the melt (B) and the removal of organic volatiles (C) are carried out in a continuous kneader reactor with kneading bars, some of the which are arranged so as to recirculate the material towards the reactor inlet. Independent claims are also included for a kneader reactor for this process, with two parallel shafts (8, 9) carrying discs (10) fitted with peripheral kneading bars (11, 12) for transporting the mixture, a casing with at least two inlets and a product outlet, a drive system for synchronous or contra-rotation of the shafts and a heating/cooling system, some of the kneading bars being fitted at an angle (with reference to the machine direction) such that the product is moved from the outlet end towards the inlet moulding materials (II) made from (I) moulded products made from (II).